How does DubStat calculate wrestling Elo ratings?

DubStat’s Elo Rating system is derived from the original system developed in the 1960’s by Physic Professor, Arpad Elo, in order to rate the skill level of chess players.

However, DubStat’s system has some key adjustments that make it suitable for wrestling.

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See What are Elo Ratings and How do they Work? for an introduction into Elo Ratings.

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Factors of the Elo Rating System

• Data Source
• Initial Rating
• K-factor
• Scaling factor
• Win Factor (W-Factor)

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Data Source

In order for an Elo system to work, there must be a centralized database of match results.

The data used to calculate DubStat’s Elo ratings comes multiple sites and is consolidated into a single database which comprises ~90% of the results throughout Ohio.

Below are the most common situations when results do not make it into our database:

• Dual meets – most dual meets do not get uploaded anywhere. At best they make it into a local newspaper.
• Tournaments run by hand – results from tournaments that are run by hand often do not get uploaded digitally. When they do, names are generally misspelled and results are not complete.

If you would like to see the database more complete, you can help by gathering results that are not entered and properly format them to be uploaded.

Email me at dubstatwrestle@gmail.com for more information on how you can help with data completeness. You can also enter dual meet results using this form.

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Initial Rating

A wrestler must have four matches in the database to receive an initial Elo rating.

DubStat’s algorithm calculates what the wrestler’s Elo rating “should have been” given the results of their matches and their opponents Elo rating.

After the initial rating is given, the wrestler’s score will go up or down after each match based on a few factors.

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K-factor

The k-factor is the maximum amount of Elo points a wrestler can gain (or lose) at the conclusion of a match.

In DubStat’s system, k-factor is 75 points.

While 75 points is the most a wrestler can gain (or lose), a much smaller number is usually achieved based on a few other factors.

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Scaling Factor

The scaling factor determines how likely a wrestler is to win based on the difference between their Elo rating and their opponent’s Elo rating.

For example, the algorithm may calculate that Wrestler A (1700 Elo Rating) has a 90% chance of winning against Wrestler B (1600 Elo rating).

If Wrestler A wins, they would only be eligible to gain 10% of the k-factor, or 7.5 points (10%*75 =7.5). Wrestler B would be eligible to lose 7.5 points.

If Wrestler B wins, they would be eligible to receive 90% of the k-factor, or 67.5 points (90%*75 = 67.5). Wrestler A would be eligible to lose 67.5 points.

However, there is one more factor that impacts the number of Elo points a wrestler gains (or loses) at the conclusion of a match.

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W-factor

The w-factor is custom to DubStat’s rating system. This factor accounts for how dominant a wrestler is in a match.

The w-factor determines what percentage of the max points (k-factor) should be available after a win.

Tech Falls and Pins give the highest percentage of points, Majors give out the next highest amount, and Decisions give out the lowest percentage.

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An Example

Below is an actual sample from the system that shows how a wrestlers Elo rating can change throughout a season.

W/L	RESULT	Elo	OppElo	Elo Change
W	D 4-3	1603	1575	+16
W	F 3:40	1619	1516	+5
L	D 5-4	1624	1536	(41)
L	F 1:01	1583	1702	(4)
L	D 6-3	1579	1604	(18)
W	F 0:44	1561	1440	+4
W	F 1:44	1565	1555	+30
L	M 10-2	1595	1730	(3)
W	D 7-2	1592	1597	+21
W	F 2:01	1613	1576	+14
W	T 16-1	1627	1439	+1
W	F 1:20	1628	1527	+6
W	D 8-7	1634	1599	+14
W	D 8-1	1649	1582	+10

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What is a good Elo rating?

An Elo score of 1500 is considered an “average score”. The following table is, in general, a good representation of how Elo ratings compare to achievement levels.

Achievement Level	Elo Rating (Boys)	Elo Rating (Girls)
Varsity	1500	950
District Qualifier	1575	975
State Qualifier	1675	1100
State Placer	1725	1150
State Champion	1850	1275
Superstar	1900	1300

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